The Veterans Affairs Implantable Insulin Pump Study: Effect on cardiovascular risk factors

William C Duckworth; Christopher D Saudek; Anita Giobbie-Hurder; William G Henderson; Robert R Henry; David E Kelley; Steven V Edelman; Franklin J Zieve; Robert A Adler; James W Anderson; Robert J Anderson; Bruce P Hamilton; Thomas W Donner; M Sue Kirkman; Nancy A Morgan; The Department of Veterans Affairs Implantable Insulin Pump Study Group

doi:10.2337/diacare.21.10.1596

Original Articles

The Veterans Affairs Implantable Insulin Pump Study: Effect on cardiovascular risk factors

William C Duckworth, MD ,
Christopher D Saudek, MD,
Anita Giobbie-Hurder, MS,
William G Henderson, PHD,
Robert R Henry, MD,
David E Kelley, MD,
Steven V Edelman, MD,
Franklin J Zieve, MD, PHD,
Robert A Adler, MD,
James W Anderson, MD,
Robert J Anderson, MD ,
Bruce P Hamilton, MD,
Thomas W Donner, MD,
M Sue Kirkman, MD ,
Nancy A Morgan, RPH, MBA and
The Department of Veterans Affairs Implantable Insulin Pump Study Group

Omaha Veterans Affairs Medical Center Omaha, Nebraska
University of Nebraska Medical Center Omaha, Nebraska
Creighton University Omaha, Nebraska
Johns Hopkins University School of Medicine Baltimore, Maryland
Baltimore Veterans Affairs Medical Center and University of Maryland School of Medicine Baltimore, Maryland
Cooperative Studies Program Coordinating Center, Hines Veterans Affairs Medical Center Hines, Illinois
San Diego Veterans Affairs Medical Center and the University of California San Diego, California
Pittsburgh Veterans Affairs Medical Center and the University of Pittsburgh Medical Center Pittsburgh, Pennsylvania
Richmond Veterans Affairs Medical Center and the Medical College of Virginia Richmond, Virginia
Lexington Veterans Affairs Medical Center and the University of Kentucky Lexington, Kentucky
Durham Veterans Affairs Medical Center, Duke University Durham, North Carolina
Indiana University School of Medicine Indianapolis, Indiana
Cooperative Studies Program Central Research Pharmacy Coordinating Center Albuquerque, New Mexico

Address correspondence and reprint requests to William C. Duckworth, MD, University of Nebraska Medical Center, 600 S 42nd St., Omaha, NE 68198-3020. E-mail: wduckwor{at}unmc.edu

Diabetes Care 1998 Oct; 21(10): 1596-1602. https://doi.org/10.2337/diacare.21.10.1596

Abstract

OBJECTIVE To determine whether implantable insulin pump (IIP) and multiple-dose insulin (MDI) therapy have different effects on cardiovascular risk factors in insulin-requiring patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS A randomized clinical trial was conducted at seven Veterans Affairs medical centers in 121 male patients with type 2 diabetes between the ages of 40 and 69 years receiving at least one injection of insulin per day and with HbA_lc levels of ≥8% at baseline. Weights, blood pressures, insulin use, and glucose monitoring data were obtained at each visit. Lipid levels were obtained at 0, 4, 8, and 12 months, and free and total insulin levels were obtained at 0, 6, and 12 months. All medications being taken were recorded at each visit.

RESULTS No difference in absolute blood pressure, neither systolic nor diastolic, was seen between patients receiving MDI or IIP therapy, but significantly more MDI patients required antihypertensive medications. When blood pressure was modeled against weight and time, IIP therapy was significantly better than MDI therapy for systolic blood pressure in patients with BMI <33 and for diastolic blood pressure in patients with BMI >34 kg/m². Total cholesterol levels decreased in the overall sample, but IIP patients exhibited significantly higher levels than MDI patients. Triglyceride levels increased over time for both groups, with IIP patients having significantly higher levels than patients in the MDI group. BMI was a significant predictor of, and inversely proportional to, HDL cholesterol level. No difference in lipid-lowering drug therapy was seen between the two groups. Free insulin and insulin antibodies tended to decrease in the IIP group as compared with the MDI group. C-peptide levels decreased in both groups.

CONCLUSIONS IIP therapy in insulinrequiring patients with type 2 diabetes has advantages over MDI therapy in decreasing the requirement for antihypertensive therapy and for decreasing total and free insulin and insulin antibodies. Both therapies reduce total cholesterol and C-peptide levels